1. Field of the Invention
The disclosure relates to a light emitting device.
2. Description of the Related Art
As disclosed in JP 2011-222603 A, for example, there has hitherto been employed a lead frame with a reflective film of Ag or Ag alloy plating formed on its surface in light emitting devices using a light emitting element as a light source such as a light emitting diode (LED), in order to enhance the light extraction efficiency.
The light emitting device using such a reflective film, however, has the drawback that silver crystal grains grow due to a thermal history of an assembly process of the light emitting device to increase pits and projections on its surface, reducing a reflectivity of the reflective film, resulting in reduction in light extraction efficiency.
JP 2010-153825 A discloses a lead frame including a main body made of Cu or a Cu alloy, and an Ag plating film formed on the main body with nanoparticles arranged between Ag crystal grains of the Ag plating film. The Ag plating film is not considered as the reflective film for the light emitting device.